Fig. 2

Type-A wood sourcing for WHS: Opportunistic sources such as urban natural wood residuals (NWR) that would decompose within a short amount of time (Baseline scenario, red-dashed line), whereas a WHS project (Project scenario, green line) stores it semi-permanently. The difference between the two scenarios (Project minus Baseline) is the carbon gain that serves as the basis for carbon accounting. Photo: Urban wood collected at the municipal public works facility, City of Takoma Park, Maryland. Photo by Ning Zeng